The present invention relates to burglarproof sash windows, and more specifically to a sash for a sash window which has a metal inner frame with intersected metal bars on the inside that prohibit burglars from breaking in.
A regular sash window 2, as shown in FIG. 3, comprises two sashes 21 holding a respective window glass 22, and a snap 23 mounted on one sash 21 and controlled to engage a locating groove 231 on the other sash 21, permitting the sashes 21 to be locked. This structure of sash window 2 is not safe in use because the window glass 22 cannot stop a burglar from breaking in. If to protect against burglars, a metal window shall be mounted on the outside wall over the sash window. However, the installation of a metal window on the outside wall of a building destroys the sense of beauty of the outer appearance of the building.